1. Field of the Invention
The present invention relates to an antibiotic Actinomadura-L-31 A, B and a preparation thereof. The antibiotic Actinomadura-L-31 A, B are novel sulfur-containing peptide antibiotics.
2. Description of the Prior Arts
Certain sulfur-containing peptide antibiotics have been known. The typical known sulfur-containing peptide antibiotics include Thiopeptin (J. Antibiot 23, 113 (1970)), Thiostrepton (Antibiotics Annual, p 554 (1955/56)), Taitomycin (J. Antibiot, A 12 1, (1959)), Siomycin (J. Antibiot, 22 364 (1969)), Pepthiomycin (J. Antibiot, 21 429 (1968)), Gardimycin (J. Antibiot, 29 501 (1976)), Kobenomycin (J. Antibiot, 21 320 (1968)), Leucinamycin (J. Antibiot, A 20 194 (1967)), Macromomycin (J. Antibiot, 21 44 (1968)), and Neocarzinostatin (J. Antibiot, A 18, 68 (1965)).